Thailand operates 156 national parks under the Department of National Parks, Wildlife and Plant Conservation, covering approximately 64,000 square kilometers or 12.5 percent of the country's total land area. The first national park, Khao Yai, received designation in 1962. Marine parks protect an additional 1,200 square kilometers of coastal and island environments. The protected area system divides into terrestrial parks, marine parks, wildlife sanctuaries, and non-hunting areas. Park fees follow a two-tier pricing structure where Thai nationals pay 20-40 baht per person and foreign visitors pay 200-400 baht depending on the park. Children under 14 receive 50 percent discounts in both categories. The Department of National Parks employs approximately 12,000 staff members across all protected areas. Annual visitation to all national parks combined exceeds 15 million people, with Khao Yai, Erawan, and Doi Inthanon receiving the highest numbers.
Khao Yai National Park spans 2,168 square kilometers across four provinces: Nakhon Ratchasima, Prachinburi, Saraburi, and Nakhon Nayok. The park elevation ranges from 400 meters at the lowest point to 1,351 meters at Khao Rom summit. UNESCO designated Khao Yai as part of the Dong Phayayen-Khao Yai Forest Complex World Heritage Site in 2005. The park contains approximately 3,000 plant species, 320 bird species, and 66 mammal species including Asian elephants numbering around 300 individuals, gaur, Malayan sun bears, and clouded leopards. Thirteen waterfalls exist within park boundaries, with Haew Narok Falls dropping 150 meters in three tiers and Haew Suwat Falls reaching 25 meters in height. The park road extends 47 kilometers from the north gate to the south gate, passing three visitor centers. Average annual rainfall reaches 2,100 millimeters concentrated between May and October. Temperatures range from 10 degrees Celsius during December and January nights to 32 degrees Celsius during April afternoons. The park receives approximately 1.2 million visitors annually. Five campgrounds provide 200 tent sites total. Accommodations include eight guesthouses and bungalows operated by the park service totaling 68 rooms. Night safari drives depart from the visitor center at 1900 hours when permitted. The park closes temporarily during periods of high elephant activity on roads, typically happening without fixed schedules.
Erawan National Park covers 550 square kilometers in Kanchanaburi Province, established in 1975. The park takes its name from Erawan Falls, a seven-tiered waterfall spanning 1,500 meters in total distance with individual tiers ranging from 5 to 25 meters in height. The first tier sits 500 meters from the park entrance, while the seventh tier requires a 2-kilometer hike gaining 200 meters in elevation. Water flows year-round from the Mondokthong and Rai-ong springs, though volume decreases 40 percent during February through April. The falls receive approximately 700,000 visitors annually, concentrated heavily on weekends and Thai public holidays when daily visitors exceed 5,000 people. Park regulations prohibit swimming above tier four due to steep terrain. Fish populations in the lower pools include Tor tambroides, which nibble dead skin from visitors' feet, leading to the pools' popular use as natural exfoliation sites. The park contains approximately 180 bird species and mammals including macaques, wild pigs, Asiatic black bears, and occasional tigers migrating from adjacent Sai Yok National Park. Three nature trails extend from 2 to 8 kilometers in length. The park headquarters sits 1.5 kilometers from the waterfall entrance. Bungalows provide 12 units sleeping 4-8 people each. Camping areas accommodate 50 tents. The nearest town, Kanchanaburi, lies 65 kilometers north requiring 90 minutes by road. Public songthaews operate from Kanchanaburi bus terminal to the park entrance departing at 0800 and returning at 1600, charging 50 baht per person one-way. Private transport remains necessary for visiting outside these times.
Doi Inthanon National Park encompasses 482 square kilometers in Chiang Mai Province, established in 1972. The park contains Doi Inthanon, Thailand's highest mountain at 2,565 meters above sea level. The mountain name honors King Inthawichayanon, Chiang Mai's last monarch, who died in 1897 and requested preservation of the watershed forests. A paved road reaches the summit where the Royal Thai Air Force maintains a radar station. Temperature at the summit averages 12 degrees Celsius year-round, dropping to 5 degrees Celsius during December and January nights, occasionally reaching 0 degrees Celsius during cold snaps. The summit receives approximately 2,500 millimeters of rain annually, supporting montane evergreen cloud forest. Mae Klang Falls drops 100 meters in a single tier located 8 kilometers from the park entrance. Wachirathan Falls descends 80 meters with a base pool popular for photography, situated 21 kilometers from the entrance. The park protects 362 bird species, representing more than half of Thailand's total bird species, including the green-tailed sunbird found only above 1,800 meters elevation. The King and Queen Pagodas, built in 1987 and 1992 respectively, honor King Bhumibol Adulyadej and Queen Sirikit on their 60th birthdays. The pagodas sit at 2,200 meters elevation surrounded by ornamental gardens containing temperate species including roses and salvias that do not naturally occur in Thailand. The Royal Agricultural Station Inthanon operates research plots between 1,300 and 2,200 meters focusing on temperate vegetable and flower production for highland agriculture. Two nature trails totaling 6 kilometers in length begin near the summit. The park headquarters sits at Chom Thong district 58 kilometers southwest of Chiang Mai city center, requiring 90 minutes by road. Accommodations include three sets of bungalows with 18 units total and camping areas for 30 tents. Tour operators in Chiang Mai offer day trips to the park starting at 1,500 baht per person including transport and guide.
Khao Sok National Park covers 739 square kilometers in Surat Thani Province, established in 1980. The park protects mainland Thailand's largest remaining primary rainforest, with some botanical surveys suggesting the forest age exceeds 160 million years, predating the Amazon basin. Annual rainfall averages 3,500 millimeters, with some areas receiving up to 4,000 millimeters, making this among Thailand's wettest locations. The park contains limestone karst formations rising up to 960 meters above sea level, with cliffs reaching 300 meters in vertical height. Cheow Lan Lake, created by the Ratchaprapha Dam in 1982, covers 165 square kilometers within park boundaries. The lake depth reaches 90 meters at the dam wall. More than 100 limestone islands rise from the lake surface. Raft houses provide overnight accommodation on the lake, with 15 private operators offering approximately 100 floating bungalows total. Park regulations require all raft houses to connect to centralized waste collection systems and prohibit discharge into the lake. Elephant populations in Khao Sok number approximately 150 individuals. The park represents one of the few remaining habitats for Malayan tapirs in Thailand, though population estimates remain uncertain between 20 and 40 individuals. Rafflesia kerrii, a parasitic flower reaching up to 90 centimeters in diameter, blooms in the park during January through March, though flowering remains unpredictable and individual flowers last only 5 to 7 days. The park recorded 5 percent of global bird species including all eight Thai hornbill species. The main park entrance sits on Route 401 between Takua Pa and Surat Thani, positioned 109 kilometers from Surat Thani and 172 kilometers from Phuket. Public buses from Surat Thani to Khao Sok operate hourly from 0700 to 1600, charging 90 baht for the two-hour journey. Private minibus services from Phuket take three hours and cost 500 baht per person. The park headquarters area contains four campgrounds with 40 tent sites and 20 bungalows sleeping 2 to 6 people. Access to Cheow Lan Lake requires 65 kilometers of road travel from park headquarters to the Ratchaprapha Dam pier, taking 90 minutes.
Mu Ko Ang Thong National Park comprises 42 islands covering 102 square kilometers in the Gulf of Thailand, with marine areas representing 84 square kilometers of the total. The park received designation as Thailand's second marine national park in 1980. The islands sit 31 kilometers west of Koh Samui and 19 kilometers southwest of Koh Phangan. Limestone formations date to the Permian period approximately 250 million years ago. The highest point, on Koh Wua Talab, reaches 396 meters above sea level. Emerald Lagoon, located on Koh Mae Ko, contains a saltwater lake to 250 meters long and 350 meters wide surrounded by 50-meter limestone cliffs. The lagoon connects to the sea through underground passages, causing water levels to fluctuate with tides though surface connection does not exist. Park regulations prohibit swimming in the lagoon to prevent ecosystem disruption. The park protects 16 mammal species including dusky langurs, wild pigs, and fishing cats. Marine environments contain approximately 50 hard coral species at depths between 3 and 10 meters. Coral bleaching events in 2010 and 2016 damaged approximately 40 percent of shallow corals, with recovery ongoing. The park headquarters sits on Koh Wua Talab, offering 20 bungalows and camping facilities for 50 tents. Park closure occurs annually from November 1 to December 15 due to monsoon conditions creating hazardous sea states. Day trips from Koh Samui operate from December 16 through October 31, departing at 0830 and returning at 1700, costing 1,800 to 2,500 baht per person including boat transport, national park fee, lunch, and snorkeling equipment. Tour boats require 90 minutes to reach the park from Koh Samui piers. Independent travel requires chartering private boats from Bang Rak pier on Koh Samui, costing approximately 8,000 baht for vessels accommodating up to 10 passengers.
Tarutao National Marine Park spans 1,490 square kilometers across 51 islands in the Andaman Sea near the Malaysian border, established in 1974 as Thailand's first marine national park. Koh Tarutao, the largest island, covers 152 square kilometers with mountainous terrain reaching 713 meters at Khao Chin. The island served as a penal colony from 1939 to 1948, holding up to 3,000 prisoners including political detainees. Supply disruptions during World War II led to starvation conditions, causing some prisoners and guards to turn to piracy in the Malacca Strait until Thai naval forces ended the practice in 1946. Prison building ruins remain visible at Ao Talo Udang and Ao Talo Wao bays. The park headquarters at Ao Pante Malaka provides 20 bungalows and camping areas for 60 tents. Koh Adang, the second-largest island at 30 square kilometers, features a campground and 10 bungalows at Laem Sone. Koh Lipe, while geographically within park boundaries, operates under a special administrative status allowing permanent settlement by the Urak Lawoi sea gypsy people who number approximately 1,000 individuals on the island. Commercial development on Koh Lipe falls outside national park authority, leading to hotel and resort construction that would be prohibited on other park islands. Marine environments in the park contain over 25 percent of the world's tropical fish species, totaling approximately 1,500 species. Coral coverage averages 35 percent across the park's reefs, with healthiest formations occurring around Koh Rawi and Koh Yang where coverage reaches 60 percent. Dugongs inhabit seagrass beds between islands, with population estimates ranging from 10 to 20 individuals. The park closes to visitors annually from May 16 to October 31 due to monsoon conditions. Ferry services from Pak Bara pier in Satun Province operate only during open season, departing at 1030 and 1430 daily, requiring 90 minutes to reach Koh Tarutao and 120 minutes to reach Koh Lipe, charging 700 baht one-way per person. Speedboats reduce travel time to 30 minutes but cost 1,500 baht per person.
Kaeng Krachan National Park covers 2,914 square kilometers across Phetchaburi and Prachuap Khiri Khan provinces, making it Thailand's largest national park, established in 1981. The park adjoins Myanmar's Tanintharyi Nature Reserve, creating a combined protected area exceeding 8,000 square kilometers. UNESCO designated Kaeng Krachan Forest Complex as a World Heritage Site in 2021 despite ongoing controversy regarding historical displacement of indigenous Karen villages. Elevation ranges from 40 meters along Phetchaburi River to 1,513 meters at Panoen Thung peak. The park contains approximately 400 bird species including critically endangered white-winged duck populations estimated at 20 to 30 individuals. Large mammal populations include 200 to 250 wild elephants, 30 to 50 tigers based on camera trap surveys conducted between 2018 and 2020, and small numbers of Indochinese leopards and clouded leopards. Kaeng Krachan Reservoir covers 46 square kilometers, created by a dam completed in 1966 primarily for irrigation supply to Phetchaburi Province. The reservoir permits boat access to remote park areas, with long-tail boat rentals available at the dam for 1,500 baht per day. The phenomenon of morning fog filling the valley while hilltops remain visible above the cloud layer occurs most reliably during October through January, attracting photographers to viewpoints at Panoen Thung and Khao Prik. The park headquarters sits 57 kilometers southwest of Phetchaburi town, requiring 80 minutes by road. Public transport does not serve the park, requiring private vehicle or chartered songthaew from Phetchaburi charging approximately 800 baht one-way. Accommodations include 15 bungalows at the headquarters area sleeping 4 to 8 people and camping areas for 40 tents. The remote Ban Krang campground, accessible only by four-wheel drive vehicle during dry season, provides basic facilities for 20 tents in primary forest. Park roads become impassable during heavy rain, particularly from June through September, occasionally stranding visitors for 1 to 2 days until water levels recede.